Yesterday's United Airlines Flights Grounded Due to Computer Problems

An "IT issue" took down all domestic flights yesterday for more than two hours.

All United Airlines mainline domestic flights were temporarily grounded on Sunday evening due to a computer problem. The airline first announced the incident in a tweet at 8:06 p.m. Eastern, attributing the ground stop to "an IT issue." While United announced an hour later that the issue had been resolved, The New York Times reports that flights were affected for more than two hours, with additional flights experiencing the accumulated delays throughout the night. The airline is waiving all change fees for affected passengers for flights through January 25. Only domestic flights operated by the airline's main unit, which does not include subsidiaries or partner airlines, were grounded.

While CNN reports that the ground stop was due to "low bandwidth" in the Aircraft Communications Addressing and Reporting System (ACARS)—the IT system that planes use to communicate with United operations—many delayed passengers took to social media to express frustration at a lack of initial information from airline staff, with some even suggesting the classic fix: "Have you tried unplugging it and plugging it back in again?" Cheeky.

This isn't the first time United has been crippled by IT-related issues—international flights were delayed due to two simultaneous computer glitches in October—and other airlines have experienced similar problems in the past. One month prior, British Airways passengers at various airports worldwide were delayed for hours due to a mass outage that hit self-service check-in kiosks. In August, Delta experienced three days of delays and cancellations after an electrical fire disabled the airline's data center.

These days we have planes that eliminate jet-lag and robots that will help you navigate unfamiliar airports, so you'd think airlines would have figured out how to prevent system-wide computer crashes. So why does this keep happening? As Condé Nast Traveler's Barbara Peterson noted last year, outdated computer systems are largely to blame—a combination of airlines putting off big purchases in the face of financial struggles and the complicated process of streamlining systems in the case of big airline mergers. While the airlines figure out how to prevent these seemingly avoidable problems from happening, one Twitter user suggested United's latest marketing campaign may be in need of an update: